GREEN TEA FROM TIBET

Green tea is recognized as the most healthful beverage available. In recent years it has been described as a protector against cardiovascular disease and some cancers. It was recently reported by Paul Recer (Associated Press, April 22, 2003), that it also has the potential of being an immune enhancer:

A new study finds that tea boosts the body's defenses against infection and contains a substance that might be turned into a drug to protect against disease, researchers say. Coffee does not have the same effect, they say.

A component in tea was found in laboratory experiments to prime the immune system to attack invading bacteria, viruses and fungi, according to a study in the Proceedings of the National Academy of Sciences released yesterday. A second experiment, using human volunteers, showed that immune-system blood cells from tea drinkers responded five times faster to germs than did the blood cells of coffee drinkers.

"We worked out the molecular aspects of this tea component in the test tube and then tested it on a small number of people to see if it actually worked in human beings," said Dr. Jack Bukowski, a researcher at Brigham and Women's Hospital in Boston and Harvard Medical School. The results, he said, gave clear proof that five cups of tea a day sharpened the body's disease defenses.

Penny Kris-Etherton, a nutrition specialist at Penn State University, said the study adds to a growing body of evidence that tea is an effective disease fighter. "This is potentially a very significant finding," she said. "We're seeing multiple benefits from tea." But she said the work needs to be confirmed in a much larger study, involving more people.

In the study, Bukowski and his co-authors isolated from ordinary black tea a substance called L-theanine. Bukowski said L-theanine is broken down in the liver to ethylamine, a molecule that primes the response of an immune-system element called the gamma-delta T cell. "We know from other studies that these gamma-delta T cells in the blood are the first line of defense against many types of bacteria, viral, fungal and parasitic infections," he said. "They even have some anti-tumor activity." The T cells prompt the secretion of interferon, a key part of the body's chemical defense against infection, Bukowski said. "We know from mouse studies that if you boost this part of the immune system it can protect against infection," he said.

To further test the finding, the researchers had 11 volunteers drink five cups of tea a day, and 10 others drink coffee. Before the test began, they drew blood samples from all 21 test subjects. After four weeks, they took more blood from the tea drinkers and then exposed that blood to E. coli bacteria. Bukowski said the immune cells in the specimens secreted five times more interferon than did blood cells from the same subjects before the weeks of tea drinking. Blood tests and bacteria challenges showed there was no change in the interferon levels of the coffee drinkers, he said. Bukowski said it may be possible to further isolate and refine L-theanine from tea and use that as a drug to boost the immune system.

The health effects of tea have been extensively studied. It has been linked to lower heart disease and cancer risk through the action of flavonoids, a type of antioxidant. Other studies have linked tea to helping combat osteoporosis, the brittle bone disease, and to relieving some allergy symptoms

Those who seek the benefits of green tea naturally desire to have a pure, fresh, good tasting tea. One of the best teas is from Tibet, rich in the desired active components and grown in pristine conditions. In fact, green tea from Tibet is certified with the Green Foods mark at the Grade A level; the certification comes from the China Green Food Development Center, Beijing, and is recognized internationally. As explained poetically by the tea producer:

The bank of the Yigong Lake in the Linzhi area, Tibet
Is the production place of the Qomolangma [Himalayan Mountains] Holy Tea.
Lying by the Qomolangma, and close to the Yaluzangbu River,
Although it is in the highly frigid zone,
High as 2250m [7,000 feet] above sea level,
Enjoying the beautiful reputation of the "South of the Yaluzangbu River in Tibet."
The warm air stream coming up from the Indian Ocean to the valley of the Yaluzangbu River
Makes just the ideal conditions in the natural realm for growing the high-grade kind of tea.

The Yaluzangbu River runs over 2,000 km (1,200 miles) and turns and twists like a silver dragon from the west to the east into the valleys of south Tibet, where the tea is grown. After a 90-degree turn, the river empties into the Indian Ocean, the river valley being a natural conduit for the warm air to push up from the Ocean to this southern valley below the high Himalayan peaks. Tea grown in this area is called "Holy Tea" or "Sacred Tea," because of the strong Buddhist influence throughout the area and the sense that this unique, high mountain setting is the realm of the gods.